Canon 70D versus Canon 5D Mark III

The Canon EOS 70D and the Canon EOS 5D Mark III are two digital cameras that were officially introduced, respectively,
in July 2013 and March 2012. Both are DSLR (Digital Single Lens Reflex) cameras that are based on an APS-C (70D) and a full frame (5D Mark III) sensor. The 70D has a resolution of 20 megapixel, whereas the 5D Mark III provides 22.1 MP. Read on to find out how these two cameras compare with respect to their size, their sensors, their features, and their reception by expert reviewers.

Body comparison: Canon 70D vs Canon 5D Mark III

The side-by-side display below illustrates the physical size and weight of the Canon 70D and the Canon 5D Mark III. The two cameras are presented according to their relative size. Three consecutive perspectives from the front, the top, and the back are available. All width, height and depth measures are rounded to the nearest millimeter. You can also toggle the display to switch to a percentage comparison if you prefer that the measures are being expressed in relative terms (in this case, the camera on the left – the 70D – represents 100 percent across all the size and weight measures).

If the front view area (width x height) of the cameras is taken as an aggregate measure of their size,
the Canon 5D Mark III is notably larger (22 percent) than the Canon 70D. Moreover, the 5D Mark III is markedly heavier (26 percent) than the 70D. In this context, it is worth noting that both cameras are splash and dust-proof and can, hence, be used in inclement weather conditions or harsh environments.

The above size and weight comparisons are to some extent incomplete since they do not consider the interchangeable lenses
that both of these cameras require. A larger imaging sensor (as in the 5D Mark III) will tend to go along with bigger and heavier lenses,
while more compact options are available for the smaller-sensor camera (70D).
You can find a comprehensive overview of suitable optics in the Canon EF Lens Catalog.

The adjacent table lists the principal physical characteristics of the two cameras alongside a wider set of alternatives. In case you want to display and compare another camera duo, just click on the right or left
arrow next to the camera that you would like to inspect. Alternatively, you can also use the CAM-parator to
select your camera combination among a larger number of options.

Any camera purchase will naturally be influenced heavily by the price. The manufacturer’s suggested retail prices give an idea on the placement of the camera in the maker’s lineup and the broader market. The 70D was launched at a markedly lower price (by 66 percent) than the 5D Mark III, which puts it into a different market segment. Normally, street prices remain initially close to the MSRP, but after a couple of months, the first discounts appear. Later in the product cycle and, in particular, when the replacement model is about to appear, further discounting and stock clearance sales often push the camera price considerably down. Then, after the new model is out, very good deals can frequently be found on the pre-owned market.

Sensor comparison: Canon 70D vs Canon 5D Mark III

The size of the imaging sensor is a crucial determinant of image quality. A large sensor will tend to have larger individual pixels that provide better low-light sensitivity, wider dynamic range, and richer color-depth than smaller pixel-units in a sensor of the same technological generation. Furthermore, a large sensor camera will give the photographer more possibilities to use shallow depth-of-field in order to isolate a subject from the background. On the downside, larger sensors are more costly to manufacture and tend to lead to bigger and heavier cameras and lenses.

Of the two cameras under consideration, the Canon 70D features an APS-C sensor and the Canon 5D Mark III
a full frame sensor. The sensor area in the 5D Mark III is 156 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.6 and 1.0. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

With 22.1MP, the 5D Mark III offers a higher
resolution than the 70D (20MP), but the 5D Mark III nevertheless has larger individual pixels (pixel pitch of
6.25μm versus 4.11μm for the 70D) due to its larger sensor. However, the 70D is a somewhat more recent model (by 1 year and 4 months) than the 5D Mark III, and its sensor
might have benefitted from technological advances during this time that enhance the light gathering capacity of its pixel-units.

The 70D has on-sensor phase detect pixels, which results in relatively fast and reliable autofocus acquisition during video recording.

Consistent information on actual sensor performance is available from DXO Mark for many cameras. This service is based on lab testing and assigns an overall score to each camera sensor, as well as ratings for dynamic range ("DXO Landscape"), color depth ("DXO Portrait"), and low-light sensitivity ("DXO Sports"). Of the two cameras under consideration, the 5D Mark III offers substantially better image quality than the 70D (overall score 13 points higher). The advantage is based on 1.5 bits higher color depth, 0.1 EV in additional dynamic range, and 1.3 stops in additional low light sensitivity. The adjacent table reports on the physical sensor characteristics and the outcomes of the DXO sensor quality tests for a sample of comparator-cameras.

Many modern cameras are not only capable of taking still images, but can also record movies. The two cameras under consideration both have sensors whose read-out speed is fast enough to capture moving pictures, and both provide the same movie specifications (1080/30p).

Feature comparison: Canon 70D vs Canon 5D Mark III

Apart from body and sensor, cameras can and do differ across a variety of features. The 70D and the 5D Mark III are similar in the sense that both have an optical viewfinder.
The latter is useful for getting a clear image for framing even in brightly lit environments. The table below summarizes some of the other core capabilities of the Canon 70D and Canon 5D Mark III in connection with corresponding information for a sample of similar cameras. The full specs-sheets can be found in the camera manual or in the dpreview camera hub.

One difference between the cameras concerns the presence of an on-board flash. The 70D has one, while the 5D Mark III does not.
While the build-in flash of the 70D is not very powerful, it can at times be useful as a fill-in light.

The 70D writes its imaging data to SDXC cards, while the 5D Mark III uses Compact Flash cards. The 5D Mark III features dual card slots, which can be very useful in case a memory card fails. In contrast, the 70D
only has one slot.

Greater peace of mind: Features a second card slot as a backup in case of memory card failure.

More heavily discounted: Has been on the market for longer (launched in March 2012).

If the count of individual advantages (bullet points above) is taken as a guide, the 70D emerges as the winner of the contest (10 : 8 points). However, the pertinence of the various camera strengths will differ across photographers, so that you might want to weigh individual camera traits according to their importance for your own imaging needs before making a camera decision.

70D 10:08 5D Mark III

In any case, while the specs-based evaluation of cameras is instructive in revealing their potential as photographic tools, it says nothing about, for example, the handling, responsiveness, and overall imaging quality of the 70D and the 5D Mark III in practical situations. User reviews, such as those found at amazon, can sometimes inform about these issues, but such feedback is often incomplete, inconsistent, and biased. This is where reviews by experts come in. The table below summarizes the assessments of some of the best known camera review sites (cameralabs, dpreview, ephotozine, imaging-resource, photographyblog). The full reviews are available by clicking on the site logo in the table header.

The review scores listed above should be treated with care, though. The ratings are only valid when referring to cameras in the same category and of the same age. Thus, a score needs to be put into the context of the launch date and the launch price of the camera, and comparing ratings of very distinct cameras or ones that are far apart in terms of their release date have little meaning. Also, please note that some of the review sites have changed their methodology and reporting over time.

Other camera comparisons

Did this review help to inform your camera decision process? In case you would like to check on the differences and similarities of other camera models, just use the search menu below. An an alternative, you can also directly jump to any one of the listed comparisons that were previously generated by the CAM-parator tool. If you do not see the camera that you are looking for, please contact me, and I will try to update the database with the necessary infos.